Useful links to sites and people relating to the subjects discussed in the books:

NASA - NASA's mission is to pioneer the future in space exploration, scientific discovery and aeronautics research.
www.nasa.gov

American Astronomical Society - The American Astronomical Society (AAS), established 1899, is the major organization of professional astronomers in North America.
aas.org

SETI Institute - The Mission of the SETI Institute is to explore, understand and explain the origin, nature and prevalence of life in the universe.
www.seti.org

Associations / Clubs

Amateur Astronomers Association - Since 1927 the Amateur Astronomers Association has been serving their members and the public in all aspects of amateur astronomy.
www.aaa.org

British Astronomical Association - Formed in 1890, the British Astronomical Association has an international reputation for the quality of its observational and scientific work.
britastro.org